Abstract
As an essential nutrient, Selenium (Se) is involved in many metabolic activities including mimicking insulin function. Data on Se in various biological samples and insulin resistance are contradictory, moreover there is no large study available regarding the relationship of dietary Se intake with insulin resistance in the general population. To investigate the association between dietary Se intake and variation of insulin resistance in a large population based study, a total of 2420 subjects without diabetes from the CODING (Complex Diseases in the Newfoundland Population: Environment and Genetics) study were assessed. Dietary Se intake was evaluated from the Willett Food Frequency questionnaire. Fasting blood samples were used for the measurement of glucose and insulin. Insulin resistance was determined with the homeostasis model assessment (HOMA-IR). Body composition was measured using dual energy X-ray absorptiometry. Analysis of covariance showed that high HOMA-IR groups in both males and females had the lowest dietary Se intake (μg/kg/day) (p < 0.01), being 18% and 11% lower than low HOMA-IR groups respectively. Insulin resistance decreased with the increase of dietary Se intake in females but not in males after controlling for age, total calorie intake, physical activity level, serum calcium, serum magnesium, and body fat percentage (p < 0.01). Partial correlation analysis showed that dietary Se intake was negatively correlated with HOMA-IR after adjusting for the Se confounding factors in subjects whose dietary Se intake was below 1.6 μg/kg/day (r = -0.121 for males and -0.153 for females, p < 0.05). However, the negative correlation was no longer significant when dietary Se intake was above 1.6 μg/kg/day. Our findings suggest that higher dietary Se intake is beneficially correlated with lower insulin resistance when total dietary Se intake was below 1.6 μg/kg/day. Above this cutoff, this beneficial effect disappears.
Highlights
Selenium (Se) is an essential micronutrient element, and a key component of several selenoproteins with essential enzymatic functions that include redox homeostasis [1], thyroid hormone metabolism [2], protection from oxidative stress [3] and inflammation [1,3,4]
Based on these findings and the potential of selenoproteins to protect against oxidative stress [13], the expectation that Se might be protective against T2DM arose
Body mass index (BMI), Waist circumference (WC), Waist-hip ratio (WHR), fasting blood glucose (FBG), Fasting insulin (FINS), HOMA-IR, physical activity, serum calcium, and serum magnesium in males were significantly greater and Homeostatic Model Assessment of β-cell function (HOMA-β), TF%, AF%, GF%, BF% were significantly lower than females (p < 0.01 for all)
Summary
Selenium (Se) is an essential micronutrient element, and a key component of several selenoproteins with essential enzymatic functions that include redox homeostasis [1], thyroid hormone metabolism [2], protection from oxidative stress [3] and inflammation [1,3,4]. Data from a good number of studies suggested Se was associated with the development of type 2 diabetes (T2DM) [5,6], but the findings are contradictory. A number of cell and animal studies have provided evidence that Se has an important role in regulating glucose homeostasis [8,9,10,11,12]. Based on these findings and the potential of selenoproteins to protect against oxidative stress [13], the expectation that Se might be protective against T2DM arose. Results from randomized clinical Se supplementation trials have raised concern that high Se exposure might increase the development of T2DM [24,25,26,27], but the results were still contradictory [6]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
